Machine for polishing and burnishing real and artificial precious stones.



E. CHALLETi MACHINE FOR POLISHING AND BURNISHING REAL AND ARTlFICIAL PRECIOUS STONES. APPLICATJON HLED NOV. 10, l9l5- R'E NEWED DEC. 30, S918.

1,293,334L, Patented Feb. 4, 1919*.

Specification of Letters Patent.

Patented Feb. at, 1919.

Application filed November 10, 1915, Serial No. 60,696. Renewed December 30, 1918. Serial No. 268,876.

To all whom it may concern:

Be it known that I, ETIENNE OHALLET, citizen of Switzerland, residing at Geneva, invented certain new and recious Stones; hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to fi ures of reference marked thereon, which form a part of this specification.

In order to obtain the burnishing of the facet of a precious stone on the same grinding wheel as serves for the polishing, the Working lapidary wipes the grinding wheel near its edge in order to remove the dia-.

mond paste and he thenuses this part of the grinding wheel bearing now only extremely fine particles of the grinding material for effecting the burnishing or final polishing.

The machine forming the object of the present application enables the burnishing to be effected automatically immediately after the polishing of the stone, on the same grinding wheel.

The accompanying drawing illustrates a suitable manner of effecting the object of the invention.

Figure l is a plan view of the machine, Fig. 2 a vertical section, Fig. 3 a section on the line a2-y of Fig. 2, and Fig. 4 a similar section but showing the various parts in a difierent position to that represented in Fig. 3.

The machine illustrated comprises a lapidary wheel 1, revolving at high speed, the shaft 2 of which traverses a bearing 3 and carries a pulley 4. The shaft 2 is eccentric in the bearing and thelatter also is mounted eccentrically in a hollow sleeve 5 which it traverses and which only rotates slowly. This sleeve is mounted in a frame 6. The bearing 3 carries a pulley 7 and the sleeve 5 a screw 8 which enters a semi-circular groove 9 in the bearing 3. The screw 8 serves as a stop for actuating and the groove 9 enables the radially in the sleeve 5 and that the centering or decentering is effected, to the direction of rotation of the sleeve 5. The axial displacement of the gearing in the sleeve 5 and that of the shaft 2 in the bearing are therefore. such that by turning the sleeve 5 for a half rotation around the bearing 3 either the centering of the shaft 2 in the sleeve 4'") or the maximum decentering of the shaft 2 is produced.

The stone carriers 10 the grinding wheel; they ally and maintained in rangement not shown in allows their inclination to be varied according to the form of the stones. Eight series of three stone carriers are arranged radially forming three circular concentric rows of eight stoneearriers.

If the shaft 2 and the sleeve 5 tric (Fig. follow always the same path on the grinding are situated above are arranged radi- 211'6 COIICBH- ing of the polished facet.

If, on the other hand the shaft 2 is eccentric in the sleeve 5, it travels around the axis of this latter, following the circle 11 shown in broken lines in Fig. 4, and from this axial displacement there results a planetary movement of the grinding wheel 1 which has the eflect of double the axial displacement of the shaft 2 and of the sleeve 5. By fixing therefore the spacing between the stone carriers of a radial series in conformity with this axial displacement, the utilization of the whole active surface of th polishing of the stones Wlll be effected. In order to avoid the carried along by the friction of speed shaft 2, it may be braked.

Instead of a grinding wheel, a cylinder with rows of stone carriers arranged around it might be employed and be displaced axially for causing the whole of its surface to operate during the polishing operation. he burnishing will then be obtained by simply cylinder which will continue to rotate at high speed.

The successive polishing and burnishing of the stones according to the method hereinbefore described may evidently also be automatically efiected'by the displacement of the stone carriers, but it is more simple mechanically to displace the lapidary wheel.

Having thus describedmy said invention, what I do claim, and desire to secure by Letters Patent, is:

1. A machine for polishing and burnishing real and artificial precious stones, embodying therein a shaft, a lapidary wheel carried thereby, means whereby said shaft is continuously rotated, a carrier for the stone or stones to be polished and burnished, and means whereby a continuous relative displacement of said wheel and said carrier radially of said wheel may be effected to polish the stone or stones, or prevented to burnish, the stone or stones.

2, A machine for polishing and burnishing real and artificial precious stones embodying therein a rotatable sleeve, a bearing mounted eccentrically thereof, a shaft mounted eccentrically of said bearing, a lapidary wheel carried by said shaft, means whereby said shaft is continuously rotated, a carrier for the stone or stones to be polished and burnished, means rotating said Copies of this patent may be obtained for five cents each, by addressing the arresting the axialoscillation of the sleeve and means whereby the relative posi tion of said sleeve and said bearing may be varied to cause said shaft to describe an orbit about, or rotate concentric with, the axis of said sleeve.

3. A machine for. polishing and burnishe ing real and artificial precious stones embodying therein a rotatable sleeve, a bearing mounted eccentrically thereof and having a groove extendingpartially about: the outer face thereof, a screw carried by said sleeve and projecting shaft mounted eccentrically of said bearing, a lapidary Wheel carried by ,said' shaft, means whereby said shaft; is continuously rotated at high. speed, a carrier stone or stones to be polished and burnished, and means: whereby said sleeve may bev rotated in eitherdirectional: a speed relatively lower than the speed of rotationof said shaft, to vary the relative positions of said sleeve and said bearing to either cause said shaft to describe an orbit about, or

rotate concentric with, the axis of sa d sleeve.

In testimony, that I claim the foregoing I have hereunto setmy hand this sixteenth day of September, 1915.

ETIENNE CHALLET. Witnesses:

H. W. FRIEDLAND, R. SOLLBERGER.

"Commissioner of Patents,

Washington, D, 0;"

IHtO said groove, a.

for the 

